This research project is devoted to a basic cognitive process that leads to the gradual development of a distorted image of reality. Research sponsored by the current grant from NIMH (MH-42715) suggests that this process may play an important role in the development of perceptual biases and psychological disorders. The phenomenon to be investigated pertains to the operation of encoding algorithms (i.e., nonconscious cognitive processes responsible for "translating" objective stimuli into subjectively meaningful experiences and for triggering initial emotional responses). Findings from previous studies indicate that some encoding algorithms nonconsciously impose on stimuli certain preexisting interpretive categories or prototypes even if the stimuli "objectively" do not match the categories. This idiosyncratic interpretation of stimuli as supportive of preexisting cognitive dispositions may, in a sense, become a source of subjective experiences that are consistent with these dispositions. In this manner, the encoding algorithms (in this case the encoding bias) may gradually develop in a self-perpetuating manner. This research project is a continuation of project MH-42715, and it is partially based on experimental procedures developed for that earlier research. It is designed for a duration of three years and will address five general empirical problems regarding the nature of the self-perpetuation phenomenon and its role in human adjustment: (1) The internal organization of knowledge acquired via the self-perpetuation processes, (2) The hypothesized nature of individual differences in the self-perpetuating development of encoding dispositions and their behavioral and personality consequences, (3) The dynamics of the self-perpetuating development of encoding algorithms and the limits of the self-perpetuation phenomenon, (4) The hypothesized cognitive mechanisms that normally work to protect the cognitive system from perpetuating erroneous encoding algorithms, and (5) The role of the self-perpetuating development of encoding dispositions in the development and sustenance of depression.